To carry out an exception that monks would be allowed to request donations not for their own benefit, without the invitation to declare it, would be asking for food (I guess also for the other requisites) if a fellow monk would be sick. This is of course an exception, but neither touches the issue here, nor touches requests for money and other things.
The undertaking how ever, does not respect the conditions when Bhikkhus are not allowed to teach, does not respect rules in regard of the danger of corruption, and at least does not represent the ways of the sages:
What's been chanted over with verses
shouldn't be eaten by me.
That's not the nature, brahman,
of one who's seen rightly.
What's been chanted over with verses
Awakened Ones reject.
That being their nature, brahman,
this is their way of life.
Serve with other food & drink
a fully-perfected great seer,
his fermentations ended,
his anxiety stilled,
for that is the field
for one looking for merit.
At least, if one is very attentive, he would see that a growth of generosity toward nibbana, lies within exactly this strict intention, it would bound people to repay their gratitude by their neighbors or even with there own transformation, does not close the circle of the eight persons and is the very engine of the Dhamma-Wheel. One-for-one Business and trade will always just increase the cemeteries.
That is what is meant if wise people say "don't sell out Dhamma", it does not mean that you should put a price on it, but let it be gained by means which are conductive to even grasp the basics.
Today Dhamma is taught on universities, respectless laypeople with the support of certain monks have developed huge industries around it, righteous practicing Bhikkhus get hardly support if they are not involved in Dhamma-Bussines, Generous lay-undertakings to contribute Dhamma as a gift are victims of Monk-Livelihood-and-Monastery-founding-untertakings. Not easy would a layperson have any intention to even visit a monk, some of them knowing the whole Tipitaka, not having approached a Bhikkhu yet.
It is really time to change ways and it is nonsense to run after corrupted ways of ordinary life. That requires a punch of faith as the big stream flows upward, but if not possible, he would not have said that it is possible.