I would suggest such criticism implies this event is somewhat or is, sacrosanct (at least to some), thus being analogous to traditional celebrations such as Christmas and Easter, very often criticised for being over-commercialised in places like Ireland and across the west with backlash sometimes manifesting itself where some celebrants put limits on how much they spend on gifts, or Kris Kindling it and so on.
It would not be unreasonable then to claim that such criticism actually equates this with traditional religious observances and festivals.
Such is the criticism that something is too commercial or overly commercial that it by default undermines the inherent value of the event or celebration, in the case of Christmas and Easter it’s clear but in the case of PRIDE, what is the inherent value being undermined by commercialisation?
Perhaps to answer this, you then need to assume that PRIDE is something more than normal, something worth celebrating, not for just a day but now a whole month clustered around the summer solstice no less but something truly incredible, a higher state, maybe even out of this world.
A something so unbelievably worth it that humongous corporates that spend (probably) billions on branding and marketing every year, which their entire reputational value is throughly invested and instilled in, are seemingly happy, nay gung-ho to huddle under the PRIDE rainbow and subjugate their entire BRAND image along with aligned or other competing corporates with something that appears to be well, at least more than just some innocent fun, more than a local festival but a broad set of values, beliefs, political views, ideologies, sexual preferences and sexual activities that appears to not only be in flux but expansionary in the most peculiarly exponentially relative and in some eyes utterly dangerous as the exponential way that seems to now know no bounds, socially, politically, financially, geographically and even spiritually, which I think has not been seen since, well, not slice toast, but since, well I don’t know what actually - Communism?
Maybe we all need to spend more time considering what exactly is this PRIDE thing before testing the validity of at least the first criticism.