The controversy over in-game microtransactions will have a lasting negative impact on game publishers, according to one Wall Street firm.

Cowen reiterated its market perform ratings for Activision Blizzard’s and Electronic Arts’ shares, citing increasing development costs.

“Game development times are getting longer, and R&D costs are growing faster than they had previously,” analyst Doug Creutz wrote in a note to clients Friday. “This isn’t a monopoly business … Angering your customer with bad MTX [microtransactions] does matter.”

Creutz reaffirmed his $66 price target for Activision Blizzard shares, representing 7 percent downside to Thursday’s close. He also reiterated his $104 price target for EA stock, which is 9 percent lower than Thursday’s close.

The analyst said research and development spending growth is accelerating for gaming companies. He noted R&D budgets for the four largest publishers grew at roughly a 1 percent annual rate from 2010 to 2015, then rose to more than 8 percent per year the last two years.

Creutz said the outrage over the initial money-making strategy in EA’s “Star Wars Battlefront II” likely hurt the title’s sales by 3 million to 4 million units versus the company’s 14 million guidance. He noted Activision’s “Destiny 2” player engagement is waning after the community questioned the game’s design decisions.

The “industry plans to further expand live services revenue appear to have run into some roadblocks with gamers sounding off against some recent titles, notably EA’s “Star Wars Battlefront II” and Activision’s “Destiny 2″ (though the issues with the latter go beyond just MTX),” he wrote. “We think writing off angry gamers as largely irrelevant is a mistake.”

He added:

“[Star Wars Battlefront II] has pretty clearly significantly underperformed expectations and remains without a live services revenue stream, while Destiny 2 has at the least suffered some unwanted engagement attrition. We suspect that 2018 will see a pullback on industry attempts to aggressively drive MTX growth as a result.”

The analyst also warned gaming industry stocks may falter due to high expectations.

“Current valuations are pricing in an awful lot of good news, with an investor base that seems at least somewhat complacent,” he wrote. “It’s not just that gamers are angry and complaining; there have clearly been performance consequences for the games involved. And in an industry where every company is dependent upon a relatively small number of franchises, this matters.”

Electronic Arts and Activision Blizzard did not immediately respond to requests for comment.