I mean, languages like Bluespec are very close to actual SystemVerilog semantically, and others like Clash are essentially structural by design, not behavioral (I can't speak for other alt-RTLs). You are in full control of using DFFs, the language perfectly reflects where combinatorial logic is done, the mappings of DFFs or IP to underlying RTL and device primitives can easily be done so there's no synthesis ambiguity, etc. In the hands of an experienced RTL engineer you can more or less exactly understand/infer their logic footprint just from reading the code, just like Verilog. You can do Verilog annotations that get persisted in the compiler output to help the synthesizer and all that stuff. Despite that, you still hear all the exact same complaints ("not good enough" because it used a few extra LUTs due to the synthesizer being needy, despite the fact RTL people already admit to spending stupid amounts of time on pleasing synthesizers already.) Died-in-the-wool RTL engineers are certainly a conservative bunch, and cagey about this stuff no matter what, it's undeniable.

I think a bigger problem is things like tooling which is deeply invested in existing RTLs. High-end verification tools are more important than just the languages, but they're also very difficult to replicate and extend and acquire. That includes simulation, debuggers, formal tools, etc. Verification is where all the actual effort goes, anyway. You make that problem simpler, and you'll have a winner regardless of what anyone says.

You mention the Intel and Xilinx's software groups, but frankly I believe it's a good example of the bigger culture/market problem in the FPGA world. FPGA companies desperately want to own every single part of the toolchain in a bid for vertical integration; in theory it seems nice, but it actually sucks. This is the root of why everyone says Quartus/Vivado are shitware, despite being technically impressive engineering feats. Intel PSG and Xilinx just aren't software companies, even if they employ a lot of programmers who are smart. They aren't going to be the ones to encourage or support alternative RTLs, deliver integrated tools for verification, etc. It also creates perverse incentives where they can fuel device sales through the software. (Xilinx IP uses too much space? Guess you gotta buy a bigger device!) Oh sure, Xilinx wants you to believe that they're uniquely capable of delivering P&R tools nobody else can — the way RTL engineers talk about the mythical P&R algorithms, you'd think Xilinx programmers were godly superhumans, or they were getting paid by Xilinx themselves — that revealing chip details would immediately mean their designs would be copied by Other Electronics Companies and they would crumble overnight despite the literal billions you would need up-front to establish profitability and a market position, and so on. The ASIC world figured out a long time ago that controlling the software just meant the software was substandard.