I would say there's a difference between defending a
kit and defending a
manufacturer. I'd never consider a kit "not worth building" unless it has been superseded by a newer, better kit in the same or similar scale. There are many flawed and inaccurate kits, both new and old, that can be built into very nice models with some added work on the part of the builder.
However, I have no problems with a manufacturer being criticised when their model is seriously flawed, especially when it would have been relatively easy for them to get it right (or at least not get it as wrong as they did). Many kits often have minor errors resulting, for example, from confusion between features of different versions of the same subject, or alterations made to preserved examples in museums - but the flaws in Lindberg's I-53 appear to go very far beyond "rivet counting"; it looks like the manufacturer either did very little research at all, or based their model on a single, inaccurate source.
My personal opinion of both the Lindberg I-53 and Heller Soleil Royal kits is very similar; they're both seriously flawed kits that nevertheless can be improved into a reasonable if not perfect replica with some scratchbuilding and kitbashing work, and despite their flaws are worth considering if you have a serious interest in the subject matter and scale (otherwise, avoid); and, in both cases, they're the result of what appears to be inexcusably poor research on the part of the manufacturer (even more so with the I-53, given that photographs and plans exist of the real vessel).
If Heller released their SR kit now (or if I had been around 35 years ago when it was first released) I would be even more critical of Heller than Lindberg; whilst the I-53 has many features, starting with the hull shape, that don't much resemble the real thing, at least it doesn't have things like a nonsensical rigging plan and a bow/beakhead structure that would collapse under its own weight!