This is a big problem with charities and other donation driven organizations. People want to say where their donations go, and will often leave gifts for flashy things that can't be used for general purposes. General donations can fill in any gaps and are therefore some of the highest value donations.
No one donates and says, please restrict this donation to the purchase of basic janitorial supplies. But that doesn't change the fact they still need those supplies.
No one sets up a site begging for funding specifically for janitorial supplies, either. It’s fine to choose not to open that door if retaining the control of general pool is preferred. But it leaves human heartstrings untugged and opportunity for “crowdfund energy” donations uncollected. I hope that tradeoff pays off for them!