Yes, I read same documents for this subject.
I can see two main problem for web hosting companies.
The first problem is security architecture.
The second problem is 3rd party tools like PhpMyAdmin. And need some components.
Firebird is very stabil data base system.
I believe Firebird can be best open source data base system for on the web.

--- In firebird-support@yahoogroups.com, Kjell Rilbe <kjell.rilbe@...> wrote:
>
> Den 2011-05-24 18:25 skrev Ahmet Nuri D såhär:
> > I use firebird for network aplications. It has very hight performance
> > for network aplications. I wnat to use it for web aplications. But when
> > I ask how is firebird on the net? Everyone say that Don't use it for web
> > aplications. Because It is very slow on the net and sometimes it is
> > crash. I can't understant that. Why firebird is not populer on the net
> > like Mysql or PostgreSql?
>
> I could imagine that for many web applications there are many many
> readers and few and infrequent writers. Firebird is, as I understand,
> better suited for scenarios where there are a lot of concurrent readers
> AND writers, because that's where its MGA architecture shines.
>
> Other engines may be better suited for the "almost read-only" scenarios,
> and perhaps they can outperform Firebird by being weaker when there are
> many writers.
>
> That said, I can't imagine that many web applications would have
> performance problems with Firebird, assuming the database is adequately
> configured and indexed.
>
> For web hosts I believe I've heard/read that Firebird's security
> architecture could be a problem, but I can't off the top of my head
> think of how or why. I also think that it was supposed to be "fixed" in
> version 2.5 or the upcoming version 3.0.
>
> My recommendation if you want to host a webb app with FB is to rent a
> virtual server.
>
> Kjell
> --
> --------------------------------------
> Kjell Rilbe
> DataDIA AB
> E-post: kjell@...
> Telefon: 08-761 06 55
> Mobil: 0733-44 24 64
>