I would have to say that it is highly likely that the people making an issue of this are people who are unfamiliar with professional practise and licensing. That is because professions such as medicine and law require that you are licensed to practise in a jurisdiction: otherwise, you can be liable for unauthorised practise of law (or medicine, etc.).
If one quits the active practise of a profession for whatever reason, they may want to switch to retired or inactive status, which is different from being suspended or disbarred: although I know that being inactive, suspended, or disbarred requires the person to petition for reinstatement before resuming practise.
On the other hand, being inactive is not a statement that the person is unfit for practise: merely that they no longer practise law for whatever reason. This is the relevant section of Pennsylvania law regarding inactive status as a lawyer--204 Pa. Code § 93.146:
(b) Inactive Status. Enforcement Rule 219(j) provides that:
(1) An attorney who is not engaged in practice in Pennsylvania, has sold his or her practice pursuant to Rule 1.17 of the Pennsylvania Rules of Professional Conduct, or is not required by virtue of his or her practice elsewhere to maintain active licensure in the Commonwealth may request inactive status or continue that status once assumed. The attorney shall file either the annual form required by § 93.142(b) and request inactive status or file Form DB-28 (Notice of Voluntary Assumption of Inactive Status). The attorney shall be removed from the roll of those classified as active until and unless such inactive attorney makes a request under paragraph (3) of this section for an administrative return to active status and satisfies all conditions precedent to the grant of such request; or files a petition for reinstatement under § 89.273(b) (relating to procedure for reinstatement of an attorney who has been on inactive status for more than three years, or who is on inactive status and had not been on active status at any time within the prior three years) and is granted reinstatement pursuant to the provisions of § 89.273(b) of these rules.
(2) An inactive attorney under this subsection (b) shall continue to file the annual form required by § 93.142(b) and shall pay an annual fee of $70.00. Noncompliance with this provision will result in the inactive attorney incurring late payment penalites, incurring a collection fee for any check in payment that has been returned to the Board unpaid, and being placed on administrative suspension in accordance with the provisions of § 93.144.
(3) Administrative Change in Status from Inactive Status to Active Status: An attorney on inactive status may request resumption of active status by filing Form DB-29 (Application for Resumption of Active Status) with the Attorney Registration Office. Resumption of active status shall be granted unless the inactive attorney is subject to an outstanding order of suspension or disbarment, unless the inactive attorney has sold his or her practice pursuant to Rule 1.17 of the Pennsylvania Rules of Professional Conduct (see § 89.273(b)), unless the inactive status has been in effect for more than three years, or unless the inactive attorney had not been on active status at any time within the preceding three years (see § 89.273(b)), upon the payment of:
(i) the active fee for the registration year in which the application for resumption of active status is made or the difference between the active fee and the inactive fee that has been paid for that year; and
(ii) any collection fee or late payment penalty that may have been assessed pursuant to § 93.144 of these rules, prior to the inactive attorney’s request for resumption of active status.
Where a check in payment of the fees and penalties has been returned to the Board unpaid, the Attorney Registration Office shall immediately return the attorney to inactive status, and the arrears shall not be deemed to have been paid until a collection fee, as established by the Board under § 93.142(b)(2), shall also have been paid.
In other words, one no longer practises in that jurisdiction and does not have to pay full licence fees or take continuing legal education (CLE). That also applies to being retired (same section) although there is no fee associated with being retired. The annual fee for inactive status is less than the annual fee assessed active attorneys, and inactive attorneys are exempt from paying the additional annual fees imposed upon active attorneys.
One can be reinstated to active status from inactive by petitioning the court and paying the fees for the period of being in inactive status.
Of course, one can not take new cases or actively practise law, yet remain on the active list, but one is obligated to pay the full licence fees and take CLE to remain active (if there is a CLE requirement) as well as any other obligations which come with being licenced. Also, one cannot be listed on a firm's letterhead if one is inactive since they aren't supposed to be practising law.
Also, some jurisdictions make retirement final (as opposed to being inactive), which would mean that one would have to retake the bar if they wished to resume the practise of law.
Whether one remains active, inactive, or retired depends upon a lot of things, but ethical issues are not a part of that: the real question is more like will you be likely to practise your profession? You would be better served by keeping your licence if the answer is yes.
On the other hand, some people do not need to practise law, but may wish to resume at some future time.