So wrote Zal Bilimoria last week in post provocatively titled Our Love Affair With the Tablet Is Over.

Bilimoria, a former project manager at Google (GOOG), Microsoft (MSFT) and Netflix (NFLX), is now a partner at Andreessen Horowitz, the high-profile venture capital firm co-founded by Web pioneer Mark Andreessen.

Andreessen, it turns out, disagrees with his partner. “My iPad Retina Mini is still my third best friend,” he tweeted the next day.  Chris Dixon, another Andreessen Horowitz partner, also begged to differ. So did a host of big-footed bloggers, including GigaO’s Om Malik, Creative Strategies’ Ben Bajarin, Daring Fireball’s John Gruber and Engadget’s Mat Smith.

But where there’s smoke there may be fire. Just because Apple’s (AAPL) iPad’s sales and revenue trajectories seem healthy doesn’t mean other players in the category aren’t headed for a rough patch.

Bilimoria’s argument is based in part on his experiences at Netflix, where tablet streaming exploded but was eventually overtaken by smartphones and larger-screen “phablets.”

“The reason was obvious,” he writes. “As phone apps improved in terms of quality and speed, users abandoned their tablets for the device in their pocket that could access the Web anywhere and anytime from Wi-Fi or cellular connections…

“What I realize now is that it has been the phone all along. What we are witnessing today is a merger of phones and tablets, not just at Netflix but everywhere, which is why this decade’s attempt at tablets is nearing its death — just four years after Jobs launched the original iPad.”

Is he right? His argument would be stronger if he could back it up with some numbers. It’s hard for me to judge; I’m part of that minority — 12% of U.S. tablet owners — who use their tablets as cellular devices.